100% efficiency (+) it it possible?

Discussion on Stirling or "hot air" engines (all types)
Alphax

Re: 100% efficiency (+) it it possible?

Post by Alphax »

Tom,

It is early days yet, I have only re-run your experiment four times and the results show some scatter.

The most important finding - which is still tentative so far and needs a fair bit more work on my part - seems (so far) to be two-fold:-

FIRSTLY: I've measured the heat flow through the static engine and through the running engine. What I have found (subject to repeats and confirmation) is that both heat flows (static and running) are almost the same. There is only a very small heat difference between the two (running and static). I have to say this has come as a bit of a surprise as it implies that the running engine converts only an extremely low quantity of heat to make it run and almost all of the heat is lost - almost (but not quite) exactly the same amount that is also lost through the static engine. In other words my LTD engine is very inefficient even though it runs on a temperature difference of 30 degree C (ice at minus 10, room at 20C).

SECONDLY: I've measured the "hot side" when running on ice and it drops its temperature well below ambient during running conditions. This implies substantial heat transfer (ie loss) to the "hot" side from the ice-side by convection forced by the displacer. The quantity of heat lost by this forced convection almost exactly matches that lost by unforced convection in the static engine. To a very high degree of approximation, my working LTD engine behaves in terms of overall heat flow the same as my static LTD engine - the heat in both engine conditions (running and static) being lost by forced (running) and unforced (static) convection in the working fluid.


Anyway... all of those results are no more than provisional and preliminary, but so far I have failed to achieve the results that you did with your engine.

But I continue to work on the experiment because it is throwing up quite a few unexpected and interesting results - but not, so far, any refreezing below the running engine, just a cooling of the top ("hot") plate on both running and static engines.
Alphax

Re: 100% efficiency (+) it it possible?

Post by Alphax »

Sorry... that last post could have been a little clearer :-

The sentence:
SECONDLY: I've measured the "hot side" when running on ice and it drops its temperature well below ambient during running conditions. This implies substantial heat transfer (ie loss) to the "hot" side from the ice-side by convection forced by the displacer.

Should have said:
SECONDLY: I've measured the "hot side" when running on ice and it drops its temperature well below ambient during running conditions. This implies substantial heat transfer from the "hot" side to the ice-side by convection forced by the displacer.
Just shows I should not try to type and eat my evening meal at the same time! Basically the top (hot) plate on both engines drops below ambient temperature as they cannot absorb heat from the ambient air as fast as the cold-side/ice plate can receive heat from the top (hot) plate by convection. That appears to hold true for unforced (static) and forced (running) engine conditions - which I have to say I find surprising and would like to confirm over the next few days/weeks. It is proving to be very interesting.....
Alphax

Re: 100% efficiency (+) it it possible?

Post by Alphax »

Hi Tom,
You forgot about Q cold

That is usually assumed to be an output, but my observations suggest it may actually be an additional input

I deliberately avoided considering Qcold for a reason. The reason is not because I know your observations suggest it may actually be an input (which would be very exciting indeed if shown to be true), but because I wanted to make the point that when it comes to efficiency the Qcold can be safely ignored when efficiency is defined as E=W/Qhot. In other words, ignoring Qcold legitimately gives us the simplest possible Black Box - one input, one output and the measure of efficiency that you yourself suggested. I'm just trying to keep it simple at this stage, hope thats OK?
Tom Booth
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Re: 100% efficiency (+) it it possible?

Post by Tom Booth »

Not to be too critical, glad to see someone interested in doing something, but your report seems rather vague.

"Almost the same",

In what way does one measure "heat FLOW THROUGH" the engine? Do you possess a flow meter of some kind?

No numbers attached to that statement, no account of actual procedure or actual methodology, such as, I measured the hot side at x°c at 0:800 and the cold side was y°c at 0:805

Ran "the experiment" four times already?

My first experiment alone took days and the engine ran on ice for 33 hours.

It took almost a month before I could even start the experiment because I had to order the engines from China, the other side of the world, clearing customs and all that.

You don't disclose the type and style, make, model whatever of the engine, was it modified, did you adjust timming, use any insulation, amount of ice etc. etc. etc.

Basically no information, just assumptions like "heat flow"

You say "heat transfer TO the hot side FROM the ice side,..."

What?

Are you running experiments concurrently or serially. i.e. one engine or two, (or more).
There is only a very small heat difference between the two (running and static). I have to say this has come as a bit of a surprise as it implies that the running engine converts only an extremely low quantity of heat to make it run and almost all of the heat is lost - almost (but not quite) exactly the same amount that is also lost through the static engine
This appears to be a contradiction. "A very small difference", then "exactly the same"

I can make no sense of this. Frankly it sounds like you may be just making it up.

No photographs. No video,...

Basically there is nothing that gives any credibility to your account of alleged series of supposed experiments.

I do look forward to some actual report with some credible data. Or any data.

It seems like only yesterday you were still warming up to the idea of getting started.

You must be using very small chips of ice with no insulation or something to have run so many experiments in such a short time.
Tom Booth
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Re: 100% efficiency (+) it it possible?

Post by Tom Booth »

Alphax wrote: Mon Feb 21, 2022 11:50 am Hi Tom,
You forgot about Q cold

That is usually assumed to be an output, but my observations suggest it may actually be an additional input

I deliberately avoided considering Qcold for a reason. The reason is not because I know your observations suggest it may actually be an input (which would be very exciting indeed if shown to be true), but because I wanted to make the point that when it comes to efficiency the Qcold can be safely ignored when efficiency is defined as E=W/Qhot. In other words, ignoring Qcold legitimately gives us the simplest possible Black Box - one input, one output and the measure of efficiency that you yourself suggested. I'm just trying to keep it simple at this stage, hope thats OK?
Sorry but that response just tends to add weight to the suspicion you're just yanking my chain.
Alphax

Re: 100% efficiency (+) it it possible?

Post by Alphax »

I'm not "yanking your chain", whatever that may mean, and I'm beginning to rather resent the hostile tone of your comments. Is that your "thing"?
Tom Booth
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Re: 100% efficiency (+) it it possible?

Post by Tom Booth »

Alphax wrote: Mon Feb 21, 2022 12:40 pm I'm not "yanking your chain", whatever that may mean, and I rather resent the hostile tone of your comments.

As I have said, those are but preliminary findings, and as I've said the actual results will take weeks rather than days. Many weeks would seem like a good idea in view of your attitude at present.
There is no "hostility" on my part.

Yanking my chain would, in this context mean, leading me to believe you are studiously and conscientiously attempting to carry out the same experiments, when in actuality you have no intention to do so but are just making things up based on your own suppositions of what you assume your results would be if you a really did.

"Many weeks" to get any results, but four experiments already completed?

Your account becomes more improbable with every post you make.

Did you order engines online or build your own?

How did you calibrate the two engines, if there were two, to ensure they were really identical? Especially when dealing with such slight, hard to measure differences.

A bit of friction in one engine and not the other could throw off the results entirely.
Tom Booth
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Re: 100% efficiency (+) it it possible?

Post by Tom Booth »

Alphax wrote: Mon Feb 21, 2022 12:40 pm I'm not "yanking your chain", whatever that may mean, and I'm beginning to rather resent the hostile tone of your comments. Is that your "thing"?
No, hostility is not "my thing".

It would help if you could provide one shred of substantial, verifiable evidence that you have actually carried out any experiment at all.

Or concrete data of any kind

Type of engine used would be a start.
Alphax

Re: 100% efficiency (+) it it possible?

Post by Alphax »

I have been running preliminary experiments for 6 days, beginning the day after I asked you to confirm the details of your original experiment, in order to refine your original experiment (for example, you have too much ice and 30+ hours is too long).

The preliminaries are about optimising the size and initial temperature of the ice block (not an ice pack, as the packing density introduces variations in the melting profile and introduces liquid water convective paths between ice "lumps"). My preliminary experiments are on standardised 250 gram ice blocks in an insulated Dewar with the engine sitting directly on the top of the ice block itself to ensure intimate contact. Water run off is measured (by weight) using a microgram balance. Heat flow and heat balance is calculated from standard temperature difference and specific heat capacities of water and ice. Timing is from standard stopwatch. The LTD used is one of the most common, if not the most common on the market, and is one I had for some time prior to starting the experiments. I use the same engine in alternate static and running experiments, two of each so far (four in total). Using the same engine for control (static) heat and running heat measurements is important as eliminates concerns about differences between engines. The running tests need to be alternated back-to back (intercalated) with the static tests.

I think that once trust has become frayed or eroded there is little point in continuing the dialogue, though I will complete the work as it is interesting (to me).

The attached photograph is of the LTD engine I am using for the work, though doubtless you will say that isn't even my hand holding it, or my floor beneath it. Whatever (as I believe you say on your side of the pond). Good luck with the rest of your thread.
Attachments
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Tom Booth
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Re: 100% efficiency (+) it it possible?

Post by Tom Booth »

Thanks for the disclosures, especially the photograph which explains a lot.

Perhaps the cheapest most inefficient piece of junk ..

Sorry, but I had that engine, no bearings, the crank held in place by spring tension that is really impossible to keep constant, the piston is pressed on, so slippage while running is possible, adjusting timming (of the engine) is impossible as the crank is one piece. The six steel bolts between the hot and cold (or top and bottom plates) conducts heat readily.

You say a dewar? An actual dewar?

How were you able to get the engine to sit atop a (what size) dewar? With perfect contact with the ice... Through the entire course of the experiment? Using a small? piece of ice.

A "standard stopwatch" LOL.

So. You just sat there with a stopwatch for how long watching ice melt in a Dewar!!!! LOL

You must have a lot of time on your hands.

Can we get a photo of this setup?

What brand Dewar?

So you spring for a real dewar but use a crap engine?

Your account of experiments just keeps getting more and more preposterous.

250 grams? About a 1 cup solid block?

That is not actually much, if any less ice than I used before switching to single ice cubes, which still took nearly four hours to melt in a cheap Stainless Steel vacuum flask, which certainly conducts (and radiates) heat much more readily than an actual dewar.

Was your "Dewar" one of these:

https://www.tedpella.com/cryo-supplies_ ... _81750-500

Where did you find a Dewar that holds exactly 250 grams of a block of ice, with no air gaps?

I've not been able to locate any matching those specifications.

I have plenty of trust. If you can't handle a little criticism of your experimental procedure I'm sorry but critical analysis is part of the process and I can't even say with confidence that you actually carried out any experiment as described. based on the information you have provided.

How long did it actually take a 250 gram block of ice to melt in your Dewar?

On the stop watch? LOL

It isn't a matter of "trust", your account of your experiment just doesn't come across as believable.

I would like to believe you,.But you would need to provide some convincing evidence beyond simply "see, I have an old piece of junk Stirling engine I've had kicking around."

So what's the problem? You haven't hesitated in voicing your doubts and criticisms regarding the results of my experiments, in spite of having been largely recorded on video.
Tom Booth
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Re: 100% efficiency (+) it it possible?

Post by Tom Booth »

BTW what procedure do you follow for obtaining "standardised 250 gram ice blocks".

In My experience, Ice tends to swell as the water freezes, becoming misshapen and or rupturing/deforming the container.
Tom Booth
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Re: 100% efficiency (+) it it possible?

Post by Tom Booth »

Assuming you are sincere about wanting to replicate the experiment, from your description, you make no mention of any insulation, other than the Dewar.

If the bottom cold plate of the engine is sitting in direct contact with the ice and any part of the same cold plate is in direct communication with the surrounding ambient, then you have, in effect, a "short circuit".

In that case the ambient heat "flow" will almost entirely bypass the engine altogether passing directly across the cold plate itself instead, or at least much moreso than through the engine.

In addition, the steel bolts as already mentioned, are also highly heat conductive.

It is very likely more heat passes through any one of those bolts than through the entire body of all the working fluid, as air is absolutely the best heat insulator, second only to a complete vacuum.

To obtain any meaningful readings of the heat transfer through the working gas (air inside the engine) other avenues of potential heat transfer should be eliminated to the greatest extent possible, otherwise it will be next to impossible to detect any difference in the amount of heat being transfered in relation to running or not running.

As can be seen, in the experiments, all avenues of potential heat transfer, other than through the top plate into the working gas and down into the ice, have been either eliminated entirely or very heavily and completely insulated.

Even air gaps between the bolts are potential avenues for convective heat transfer between the top and bottom plate outside the working fluid, outside the engine.


https://youtu.be/DmkVR7hF14Y


It can be seen in these videos how the engine has had the steel bolts replaced with nylon bolts and the entire engine has been insulated, including all the small air gaps between the bolts.


Without doing all this, it may be possible to still detect some miniscule difference in the rate at which the ice melts, with the engine running or not but the difference would be so small it would be virtually non existent. The results could be thrown off by almost anything in that case, a draft in the room or body heat from briefly handling the engine etc


https://youtu.be/fwWTfyoq9rk


If you have not done this, then you cannot say that you have conducted the same experiment and got only null or inconclusive results.

Unless you make some effort to eliminate all the "short circuits" you aren't conducting the same experiment at all and no meaningful results should be expected.

No measurement can be done to show any significant difference between a running and not running when in both instances the engines are completely "short circuited", leaving enormous heat-leaks where the heat is able to pass around the engine or through conductors (metal bolts) or find other alternative wide open pathways from the ambient surounding and into the ice without passing through the working gas at all.
Nobody

Re: 100% efficiency (+) it it possible?

Post by Nobody »

Tom stated:
Perhaps the cheapest most inefficient piece of junk ..
So we can agree, that is one engine that doesn't violate the Carnot rule.

You were asking for any data that supports the Carnot law. You just agreed to one.

Hang in there Alphax. He is abrasive to all of us.

Hang in there Tom, Alphax is just trying to help. Should he get different equipment and or answers is no reason to distrust or abuse him. (The yanking chain comment is accusing him of fraud). Rather than being as defensive as you tend to be, try encouraging him.

Example: Some LTS may be more efficient than the model you are using. Some plastic screws to hold it together might help. Super insulating the whole equipment may help

I still can't get to Carnot from those videos. The one thing you've proven is that putting an engine on top of ice makes the bottom plate drop below the freezing point of water. That could come from the ice, or the bottom plate was already that cold. Percentage of heat, or efficiency, has nothing to do with it. Quantity of heat transfer, and direction do.
Nobody

Re: 100% efficiency (+) it it possible?

Post by Nobody »

If all you are trying to do is provide a new explanation as to how heat engines work, you will have to wait until someone puts it in math, data, numbers, and hardware. Even Einstein's theory's are continuously run through the skeptical mill. But it strengthens them.

If he started claiming Newton was wrong he and his theory's would have been tossed out.

Caloric theory is long dead and has nothing to do with modern thermodynamics or Carnot limits. The only problem, and reason for rejection, no calorics were found and the conservation of energy rule was supported by kinetic theory. You don't need to bring Caloric up anymore.

Carnot's theories are based on calculus and early heat engine data. Caloric theory just happened to be around at the time. Caloric being discarded doesn't make Carnot wrong. Breaking that limit will.

Springs and air springs, are not heat engines. Even if both are reversible they follow very different PV cycles. Because of that springs have zero work exiting. And they lare not 100% efficient.

From Wikipedia:
Modern gasoline engines have a maximum thermal efficiency of more than 50%,[1] but road legal cars are only about 20% to 35% when used to power a car. In other words, even when the engine is operating at its point of maximum thermal efficiency, of the total heat energy released by the gasoline consumed, about 65-80% of total power is emitted as heat without being turned into useful work, i.e. turning the crankshaft.[2]

Engines in large diesel trucks, buses, and newer diesel cars can achieve peak efficiencies around 45%.[7]

Steam engines and turbines operate on the Rankine cycle which has a maximum Carnot efficiency of 63% for practical engines, with steam turbine power plants able to achieve efficiency in the mid 40% range.
Steam turbines get only about 66% of the Carnot Limit.

Build an engine that gets 50% and people will flock to you. Claim that you've discovered how to get 100% you will be walked away from.

Tell a lie, people will both call it out and follow you no matter how outlandish the lie is.

Example of an outlandish lie, Flat Earth. Many followers. Repetitively shown to be false.

The trick is to use solid scientific methods. Science, the only method everyone uses, and the only thing capable of dispelling erroneous beliefs. Most fail at using it correctly most of the time.
Tom Booth
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Re: 100% efficiency (+) it it possible?

Post by Tom Booth »

"Nobody",

IMO there are too many incongruities in "Alfax's" account of his running the experiments.

I checked my flasks I used in the experiments. They hold under 200 grams. On the hot summer days (85°F) it took approximately 60 hours to run each experiment as the ice in a vacuum flask took between 27 and 32 hours to melt.

He said he got through FOUR experiments in such a short time because he used less ice, but claimed he used "standardized" blocks of ice that were 250 grams, which is actually MORE than I used.

He says it was 68°F (20°C) in his environment. 17 degrees cooler than during my experiments.

He also used, by his description a "Dewar," which if true,is likely much better insulation than my $5 dollar Walmart flasks.

So, how he got through a minimum of 120 experiment hours, 5 DAYS back to back experiments, (getting no sleep, holding a "stop watch") that given the colder temperature, larger volumes of ice and better insulation should have taken longer...

Until he is willing to come back and explain these and other unlikely or seemingly impossible accomplishments , especially given that just days prior to these claims he said it would likely be weeks,...

Well, sorry if my asking for a few clarifications, or asking a few questions hurt his feelings so bad he had to run away and quit the forum because I was a little skeptical..

He claims that my experiments are invalid until repeated by others then suddenly claims to have done so, "only" FOUR times already and with no apparent results.

"Just trying to help" my ass.


He is so upset that I didn't just trust him, believing whatever he said, no matter how improbable or impossible he had to quit the forum. Sure.
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